In U.S. Pat. No. 3,764,571, organotin stabilizer systems are described, particularly suited for the stabilization of vinyl halide resins against degradation by heat. Such stabilizer systems permit resins to be molded and worked under the action of heat into many useful articles. In accordance with that application, a composition comprising an organotin sulfur-containing compound, a metal carboxylate and a metal base remarkably contributes to vinyl halide resin heat stability. This three-component composition also provides for a very efficient utilization of the rather expensive organotin sulfur-containing component. Heat stabilities were achieved with the three-component novel compositions which are unobtainable at the same total levels of the individual components when used alone or in two-component combinations with one another. It was also found, as disclosed and exemplified in that application, that a metal base component, alone, contributed to the heat stabilization of vinyl halide resins in the presence of the organotin sulfur-containing compound. This application develops more fully the combination of an organotin sulfur-containing compound and a metal compound and the stabilizing synergisms embodied by such combinations.